Method and a System for Preventing a Network Storm from Presenting in a Multi-Ring Ethernet

1. A method for preventing a network storm from presenting in a multi-ring Ethernet, wherein the multi-ring Ethernet includes a plurality of nodes and a plurality of links, each link connecting one node to another node, the method comprising: dividing the multi-ring Ethernet into a plurality of single rings, each single ring defining a logic area, the logic area being associated with a set of nodes, a set of links connecting the set of nodes, and the set of links including a ring protecting link; and upon detection of a failed link in the multi-ring Ethernet: identifying, among the plurality of single rings, a single ring as being associated with the failed link; determining, for the identified single ring, a logic area and a ring protecting link associated with the logic area; and unblocking the ring protecting link; wherein at most one ring protecting link is unblocked, and one link in the multi-ring Ethernet is uniquely protected by one logic area logically, or wherein at most one ring protecting link is unblocked, shared link belongs to a plurality of logic areas, but the priorities of the logic areas are different and the shared link is protected by the logic area with the highest priority.

2. The method according to claim 1 , wherein each link in the multi-ring Ethernet belongs uniquely to one logic area that has a master node to which a ring protecting link, of the logic area is connected, and in response to a link failure in the logic area, the master node is configured to unlock the ring protecting link.

3. The method according to claim 2 , wherein a shared link between two adjacent single rings is assigned to one single ring thereof, wherein the closed single ring is a master ring, the unclosed single ring is a sub ring, and both the master ring and the sub ring are called logic areas.

4. The method according to claim 1 , wherein each link in the multi-ring Ethernet respectively belongs to multiple logic areas, each logic area is set with a priority, in response to a link failure, the multiple logic, areas associated with the failed link are identified, the ring protecting link of one logic area which contains the failed link and has a highest priority among the multiple logic areas is unblocked by the master node of the logic area.

5. The method according to claim 4 , wherein each single ring in the multi-ring Ethernet is one logic area, and each logic area has a different priority.

6. The method according to claim 1 , wherein when the failed link is the ring protecting link of a logic area, the master node of the logic area to which the failed link belongs does not perform any operation.

7. A system for preventing a network storm from presenting in a multi-ring Ethernet, the multi-ring Ethernet comprising a plurality of nodes and all nodes are connected with each other by links, the system comprising: means for dividing the multi-ring Ethernet into a plurality of single rings, each single ring defining a logic area and the logic area is associated with a set of nodes and a set of links connecting the set of nodes, the set of links including a ring protecting link; and means for, upon detection of a failed link in the multi-ring Ethernet: identifying, among the plurality of single rings, a single ring as being associated with the failed link; determining, for the identified single ring, a logic area and a ring protecting link associated with the logic area; and unblocking the ring protecting link; wherein at most one ring protecting link is unblocked, and one link in the multi-ring Ethernet is uniquely protected by one logic area logically, or wherein at most one ring protecting link is unblocked, shared link belongs to a plurality of logic areas, but the priorities of the logic areas are different and the shared link is protected by the logic area with the highest priority.

8. The system according to claim 7 , wherein each link in the multi-rings Ethernet belongs uniquely to one logic area that has a master node to which a ring protecting link of the logic area is connected, and in response to a link failure in the logic area, the master node is configured to unlock the ring protecting link.

9. The system according to claim 8 , wherein a shared link between two adjacent single rings is assigned to one single ring thereof, wherein the closed single ring is a master ring, the unclosed single ring is a sub ring, and both the master ring and the sub ring are called logic areas.

10. The system according to claim 7 , each link in the multi-ring Ethernet respectively belongs to multiple logic areas, each logic, area is set with a priority, the two nodes connected by the link record the logic areas to which they belong and the priorities of the logic areas respectively; in response to a link failure, the multiple logic areas associated with the failed link are identified, the master node of one logic area which contains the failed link and has a highest priority among the multiple logic areas unblocks the ring protecting link of the logic area.

11. The system according to claim 10 , wherein each single ring in the multi-ring Ethernet is one logic area, and each logic area has a different priority.

12. The method according to claim 2 , wherein when the failed link is the ring protecting link of a logic area, the master node of the logic area to which the failed link belongs does not perform any operation.

13. The method according to claim 3 , wherein when the failed link is the ring protecting link of a logic area, the master node of the logic area to which the failed link belongs does not perform any operation.

14. The method according to claim 4 , wherein when the failed link is the ring protecting link of a logic area, the master node of the logic area to which the failed link belongs does not perform any operation.

15. The method according to claim 5 , wherein when the failed link is the ring protecting link of a logic area, the master node of the logic area to which the failed link belongs does not perform any operation.